FontCreator doesnʼt generate otf fonts

I have this specific problem with FontCreator 14: Whenever I compile a font (which takes hours), in the end, Windows 11 claims the font is unusable/unreadable. Apparently something goes wrong during the compilation process. I tried several approaches, like “Export”, “Export as…”, etc·. My aim was to attain a viable, workable otf font, but I always ended up with an unworkable ttf font. What am I doing wrong?

I admit that the source file is kind of large, since Iʼm trying to create a “fall‑back font” for all reasonable purposes. But the compilation worked until about two years ago. Since then, none of my compilations were recognized by Windows. I really donʼt know how to create the “real‑world” comprehensive font Iʼve been working on for years. Plus, a great part of my professional work depends on this.

Is there a solution or a work‑around? Even a work‑around would suit me, since much of my work uses the precursors of my current font, only that meanwhile it has grown considerably.

Many thanks in advance for any useful hints.

We have made several improvements to exporting font files with cubic bezier curves, also known as OTF PostScript font files.

So we recommend to upgrade to the latest version.

Thanks to a simple but very effective hint by Erwin, I was able to solve my font‑compilation conundrum. I had set the check mark °Last resort font (not supported by Windows, so use with care)°, under Font Properties / Font. That really did the trick. Thx, Erwin!
I think the setting was a hang‑over from earlier versions of my font created with FC10. So if you run into this problem, check this setting first.

I realized that my latest post was not clear enough about how to go about this. Hopefully, the next line will clear up any doubts or questions about the procedure.
As I mentioned in my previous post, you have to go to Font Project, stay in the first tab, go all the way down, and you will find that check box, “Make this a fall‑back font [yada yada yada].” What I omitted is that you HAVE TO UNCHECK that box. Because the warning next to it, “Windows may not recognize this, use with care,” is absolutely true. To say it as clearly as possible: DO NOT EVER CHECK THAT BOX. Your font WILL fail.
Forgive me this oversight. I hope I corrected this before anybody got it wrong and messed up their font project!